Spark plug cutout device



Aug. 2, 1949.

T- C. KASPER ETAL SPARK PLUG CUTOUT DEVICE Filed Aug. 3, 1945 2 Sheets-Sheet 1 LJ k I q l l4 i l5 Flg. I

0 O o O o o u l O o 'Q'- \0 1 T. c. KASPER ETAL 2,477,618

SPARK PLUG CUTOUT DEVICE I Filed Aug. 3, 1945 2 Sheets-Sheet 2 3 Theodore C. Kasper D oyigl Hendry Patented Aug. 2, 1949 SPARK PLUG CUTOUT DEVICE Theodore C. Kasper and David Hendry, United States Navy Application August 3, 1945, Serial No. 608,814

(Granted under the act of March 3, 1883,'as amended April 80, 1928; 370 O. G. 757) 5 Claims.

This invention relates to testing apparatus for internal combustion engines and is particularly directed to testing equipment for determining the condition of any part of the ignition system and rendering inoperative a portion of same if found to be operating improperly or is a source of danger.

A principal object of this invention is to provide a simple, effective,.,and economical device which may be mounted permanently in an ignition system or as a portable testing unit for testing the ignition system of a multi-cylinder internal combustion engine.

A further object is to provide a testing device which may be utilized in Zrcraft to test the various compounds of the ig nition system and to cut out any part of the system that is a source of danger, such as a fire due to a cracked cylinder, etc.

These and other objects and features of the invention will be apparent from the following specification and taken with accompanying drawings wherein like numerals refer to like parts in which:

Fig. 1 is a cross sectional view taken through the device along its longitudinal axis;

Fig. 2 is a modification of the invention; and

Fig. 3 is a perspective view of a different embodiment of the invention showing the device positioned in the magneto distributor.

As shown by Fig. 1 of the drawings, numeral l refers to a metallic shielding cylindrical in shape, having openings 2 and 3 at each of the end walls. A stationary insulation core 4 is positioned within the shielding I by means of a plurality of screws 5 which secure a pair of conical shields 66 to the insulation core 4 at one end and to the cylindrical shielding I at the opening 2, 3 respectively at the other end, thus insulating the central portion of the device. Through the central part of the device there extends a plurality of high tension leads or electrical conductors I9 connecting a 1 magneto (not shown) at one end and the individual spark plugs (not shown) at the other end passing through the opening 2 and 3 and the bore 8 within the insulation core 4. A plurality of high tension lead piercing screws 9 are threaded radially through the insulation core 4 contacting each of the high tension leads II! at their inner ends, and their outer ends being flush with the surface of the core 4. Each of the piercing screws 9 are mounted in staggered relationship with each other about the circumference .of core 4 in order to obtain a maximum of insulation therebetween. Slidably mounted on the core 4 is an insulator 2 cylinder III to which is attached an actuating rod I I slidably mounted on the shielding I and passing through the nuts I2 and I3 fixed on each of the end walls .of the shielding I. The actuating rod II may be manually operated or connected to a solenoid for remote control operation.

A pluralityof leads or electrical conductors I4 extend longitudinally through a portion of the cylinder ID with their ends in contact relation with piercing screws l5 each of which mate with the piercing screw 9 in the insulated core 4. The leads I4 extend through an opening IS in the shielding I and are connected at their free ends to a selector switch I! which has a rotatable selective arm I8 grounded at one end for selectively grounding any one of the spark plugs in its igni= tion system. In the position shown by Fig. 1 with the actuating rod II in its extreme left position the device is ready for testing. To place the device in its neutral or non-operating position, the actuating rod I I is actuated to its extreme right position placing the piercing screw 9 and I5 out of contact with each other.

Normally during the operation of the internal combustion engine the device, which is installed on the main ignition cables on the output side of the magneto, has its cylinder I0 in its neutral operating position and the selective arm I8 of the switch I] is positioned in its neutral or nongrounding position. To operate the device, the actuating rod I I is actuated causing the insulator cylinder ID to move to the left and the piercing screws 9 and I5 coming in contact with each other. The selector arm I8 is rotated to the first contact or to the contact of that cylinder or spark plug believed to be operating improperly. This grounds out the selected spark plug so that the engine will indicate poorer operation by producing fewer R. P. M.s if the spark plug or cylinder had been operating properly or cause no change in R. P. M.s if the fault is in that portion of the ignition system. In a relative brief period of time the entire bank of cylinders including the spark plugs can be checked individually. A quick change of a spark plug in that portion .of the ignition system that operated improperly will further indicate if the defect was in the spark plug, in the high tension lead, or in the cylinder itself.

In a modification shown in Fig. 2 the device is simpler and more compact in construction than that shown in Fig. 1, and except for the selector switch, this device has no moving parts. In this device the leads 20 extend longitudinally through a plurality of bores 22 in the insulator core 2|.

3 The bores 22may be arranged in one or more circles and in staggered relation with each other to provide a maximum of insulating material therebetween. On each side of the insulation core 2| there is a conical shield 23 secured by screws 24 to the core 2| and having a threaded inlet 38 at its free end to receive the high tension leads 2!]. Each of the leads 20 are connected by means of piercing screws 21 to a second lead 25 that extends toa selector switch 26. A shielding 28 is secured around the core 2| to inclose the connections made by the piercing screw 21. A threaded outlet 29 is provided on the shielding 28 through which the leads 25 extend. In this modification, the leads 25 are always in contact relation with the high tension lead 20 and the arm 30 of the selector switch 26 is normally maintained in a neutral position as shown. As the arm 30 of the selector switch 26 is rotated to one of the contacts thereon, that portion of the ignition system is grounded out. As herein before described, the engine will give an indication as to whether the trouble is or is not in that spark plug or cylinder.

Fig. 3 shows a modification oi the present invention wherein the device is mounted directly on the magneto distributor 31 of an internal combustion engine having a distributor rotor 3|. A plurality of piercing screws 32 are set in the magneto block contacting on one end each of the high tension leads 36 that extend to the spark plug. The leads 33 which extend to a selective switch 34 are connected to the free end of each of the piercing screws 32. The selective switch 34 has a neutral or non-operating position wherein the arm 35 is out of contact with any of the leads 33. In the operation of this device, the arm 35 of the selector switch 34 is rotated to each of the contact positions, thus grounding out that portion of the ignition system and testing same as in the aforementioned devices.

The invention is so constructed that by mounting it permanently in an internal combustion engine, it can be used during the normal operation of the engine such as during the flight of an airplane, since only one line is grounded out at a time. Also, the invention may be constructed as a portable testing unit permitting a quick but efl'icient test of the ignition system.

While the forms of mechanism herein shown and described, constitute the preferred forms of embodiment of the present invention, it is to be understood that other forms might be adopted all coming within the scope of the claims which follow.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What we claim is:

1. A testing device for selectively testing the ignition system of an internal combustion engine comprising a high tension lead, a second lead, means including a sliding contact connecting one end of said second lead to said high tension lead, a selector switch, means connecting said other end of said second lead to said selector switch,v

and means for selectively operating said selector switch.

2. A device of the class described comprising an insulated core having a plurality of openings therethrough, a plurality of high tension leads extending through said openings, piercing screws threaded in said core in contact relation with each each of said piercing screws mating with and in contact relation with each of said piercing screws on said core, said electric conductors connected at their free ends to a selector switch, means for operating said selector switch, and means for slidably actuating said cylinder to place said piercing screws on said cylinder each in contact relation with said piercing screws in said core.

3. A device of the class described comprising an insulated core having a plurality of openings therethrough, a plurality of high tension leads extending through said core, a plurality of piercing screws in said core in contact relation with each of said high tension leads, a plurality of electric conductors connected at one end to each of said piercing screws and to said selective switch at the other end, and means for selectively operating said selector switch.

4. A testing device for selectively testing the igmtion system of an internal combustion engine provided with a high tension current distributor, comprising a housing member provided with end closures, an insulating block within said housing, a frusto-conical tubular member rigidly attached to each end closure of the housing, extending inwardly of said housing and adapted to support said insulating block, a plurality of openings in said block extending therethrough longitudinally of said housing, a plurality of high tension leads extending through the openings in said insulating block, through said housing and adapted to be connected at their ends to said distributor and each spark plug of said engine, respectively, pierc ing screw means aligned with each opening through said block, adapted to threadedly engage said block and to pierce and make an electrical contact with the high tension lead extending through the opening, the heads of said screws being flush with the exterior surface of said block, an insulating sleeve adapted to fit around and to slidably engage said insulating block, openings in said sleeve in longitudinal alignment with the openings in said block, conductors extending into the openings in said sleeve, piercing screw means aligned with each opening in said sleeve, adapted to threadedly engage said sleeve and to pierce and make electrical contact with the conductor in said opening, the head of said screw being flush with the interior surface of said sleeve and in alignment with the headof a screw in the said block, rod means connected to said sleeve for moving it with respect to said block thereby making or breaking the electrical contact of the said screw heads, a selector switch provided with a plurality of contacts connected to the ends of the conductors and a grounded, pivoted switch armature adapted to selectively contact any one of the said contacts and to thereby ground the high tension lead connected to that contact.

5. A testing device for selectively testing the ignition system of an internal combustion engine comprising: a housing; an insulating block mounted within said housing; a plurality of openings in said block extending therethrough longitudinally of said housing; a plurality of high tension leads extending through said openings and said housing and adapted to be connected at their ends to the distributor and spark plugs of said engine, respectively; piercing screw means in said block and in electrical contact with said leads; an insulating sleeve surroundingand slidably engaging said block, said sleeve having openings therein; conductors extending into the openings in said sleeve; piercing screw means in said sleeve and in electrical contact with said conductors, said screw means in said sleeve being in alignment with said screw means in said block; means for slidably moving said sleeve whereby making or breaking the electrical contact of said screw means is efiected; and a grounded selector switch having a plurality of contacts, each of said contacts being selectively connectible to said conductors.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,968,464 OBrien July 31, 1934 1,977,703 Swartwout Oct. 23, 1934 10 2,067,681 Rockwell Jan. 12, 1937 FOREIGN PATENTS Number Country Date 139,829 Great Britain Mar. 18, 1920 174,185 Great Britain Jan. 19. 1922 

